1. Technical Field
The present invention relates to printing devices that perform printing onto a sheet and the like, and in particular relates to a technique to reduce the noise generated by the printing devices.
2. Background Arts
There is conventionally known printing device having a feeding mechanism, in which a sheet extracted from a sheet feed stand is fed toward a printing section including an inkjet head and the like by a registration roller.
In this printing device, a sheet is abutted against the registration roller and stopped once so as to form sag in the sheet, and then an oblique motion of the sheet is corrected. Then, the printing device drives the registration roller at a predetermined timing to feed the sheet to the printing section.
When a sheet is abutted against the registration roller, a hitting sound is generated. In addition, when a sheet is fed by the registration roller and sag in the sheet is released, a sound of the sheet being pulled (sheet-pulling sound) may be generated. In particular, in a printing device achieving high productivity (the number of sheets to be printed per unit time) by high-speed printing, sheets are transferred at a high speed, and therefore the hitting sound and sheet-pulling sound become louder.
There is also known a both-side printing device having a circulation path including a reverse path for reversing a sheet, in which a one-side printed sheet is reversed by transferred through the circulation path and then the other side is printed.
In this printing device, since both-side printing makes use of sheet transfer paths more than one-side printing, transfer path switching operations are needed. In addition, in order to maintain high productivity, the sheet needs to be transferred partially at a higher speed. From these factors, the driving noise of a motor and the like becomes loud during both-side printing.
As described above, in a printing device, noise is generated due to various factors. As a technique to reduce the noise generated by a printing device, Japanese Patent Laid-Open No. 6-24588 discloses a technique, in which the transfer speed of a sheet is decelerated when the sheet is detected by a detector provided in the preceding stage of a registration roller, thereby reducing the sound caused by the sheet abutted against the registration roller.